A Promising Potential of Brown Algae Sargassum polycystum as Irreversible Hydrocolloid Impression Material.

This study aimed to investigate the potential use of brown algae Sargassum polycystum as irreversible hydrocolloid (alginate) impression material. Potassium alginate extracted from Sargassum polycystum was prepared in three different compositions (14%, 15%, and 16%) and mixed with other standard components to form an alginate impression material. Prior to that, the purity of potassium alginate was quantified with Fourier Transform Infrared Spectroscopy (FTIR) analysis. As a control material, the alginate impression material from a commercially available product was used. All alginate impression materials were then applied to a die stone model. Dimensional accuracy was measured by calculating the mesiodistal width of incisors in the generated dental cast using a digital caliper 0.01 accuracy (five replications). In addition, to evaluate the dimensional stability, the impression results were poured at four different periods (immediately, 5 min, 10 min, and 15 min). An independent t-test was performed to compare the measurement results with p < 0.05 considered significant. Analytical results confirm that the impression material containing 15% potassium alginate gives the best dimensional accuracy similar to control (p > 0.05). Meanwhile, the optimal dimensional stability was produced in the impression material containing 16% potassium alginate. Our study suggested that brown algae Sargassum polycystum has a promising potential to be used as an alginate impression material in clinical application.

An Innovative Customized Biomimetic Hydrogel for Drug Screening Application Potential: Biocompatibility and Cell Invasion Ability.

The ability of Pluronic F127 (PF127) conjugated with tetrapeptide Gly-Arg-Gly-Asp (GRGD) as a sequence of Arg-Gly-Asp (RGD) peptide to form the investigated potential hydrogel (hereafter referred to as 3DG bioformer (3BE)) to produce spheroid, biocompatibility, and cell invasion ability, was assessed in this study. The fibroblast cell line (NIH 3T3), osteoblast cell line (MG-63), and human breast cancer cell line (MCF-7) were cultured in the 3BE hydrogel and commercial product (Matrigel) for comparison. The morphology of spheroid formation was evaluated via optical microscopy. The cell viability was observed through cell counting Kit-8 assay, and cell invasion was investigated via Boyden chamber assay. Analytical results indicated that 3BE exhibited lower spheroid formation than Matrigel. However, the 3BE appeared biocompatible to NIH 3T3, MG-63, and MCF-7 cells. Moreover, cell invasion ability and cell survival rate after invasion through the 3BE was displayed to be comparable to Matrigel. Thus, these findings demonstrate that the 3BE hydrogel has a great potential as an alternative to a three-dimensional cell culture for drug screening applications.

Resin cement removal from titanium dental implant surface using a novel side-firing laser fiber and Er,Cr:YSGG irradiation.

PURPOSE: evaluate the influence of an erbium, chromium: yttrium, scandium, gallium, garnet (Er,Cr:YSGG) laser using multiple tip types, on the removal of retained cement on a titanium implant surface. METHODS: Nine titanium dental implants were coated with a non-eugenol resin composite implant cement. An Er,Cr:YSGG device at a wavelength of 2,780 nm was fitted sequentially with three laser fiber tips: (1) 6 mm long, 600 µm diameter end-firing, quartz; (2) 9 mm long, Radial-Firing Perio Tip, 500 µm diameter, quartz; and (3) 18 mm long Side-Firing Tip, 800 µm x 300 µm, sapphire. Irradiation on the implant surfaces was performed in short pulse mode (140 µsec pulse duration) with output power of 1.5 W, 50% water, 40% air, and either: (1) 15 Hz, 100 mJ/pulse; (2) 30 Hz, 50 mJ/pulse; or (3) 40 Hz, 37.5 mJ/pulse. Three trials each were completed for each of three different fiber tip types for a total of 27 trials (three trials for each of the nine groups). RESULTS: All samples in Groups 1-6 demonstrated complete removal of cement from the implant surface. SEM inspection revealed a high degree of melting of the resin composite cement on the implant surface in all samples treated with 100 mJ/pulse (Groups 1, 2, 3). At 50 mJ/pulse (30 Hz), the results of the end-firing and side-firing tips improved remarkably, with clean implant surfaces and comparatively little melting. The side-firing fiber at 50 mJ/pulse and 30 Hz provided the best overall combination of cement removal and least amount of residual melted material on the implant surface. Based on the limitations of this study, the most appropriate method of removing residual cement from a TiUnite coated titanium implant surface is by using an Er,Cr:YSGG laser device fitted with a side-firing laser tip. Laser parameters of 50 mJ/pulse and 30 Hz (1.5W average power), with at least 50% water and 40% air in the aerosolized water spray are ideal. CLINICAL SIGNIFICANCE: As the presence of peri-implantitis continues to increase in numbers and severity, it is imperative to have a predictable treatment protocol to address the large number of ailing and failing implant cases. This study offers one solution to the problem of peri-implantitis, especially if caused by retained cement. Optimal laser settings are proposed for surface decontamination and treatment.

Effect of nanostructured thin film on minimally invasive surgery devices applications: characterization, cell cytotoxicity evaluation and an animal study in rat.

BACKGROUND: Minimally invasive surgery is performed using an endoscope and other instruments including the electrosurgical units. However, concerns including surgical smoke, tissue sticking and thermal injury are remaining in electrosurgery. AIMS: Accordingly, a newly developed electrosurgical electrode coating with hydrogenated Cu-incorporated diamond-like carbon (DLC-Cu) film is purposed to improve the instrument performance. METHODS: The morphologies of DLC-Cu surfaces were characterized using transmission electron microscopy, scanning electron microscopy and atomic force microscopy. In this study, lesions were made on the liver lobes of adult rats, using a monopolar electrosurgical unit equipped with untreated stainless steel electrodes or treated-electrodes. Animals were killed for evaluations at 0, 3, 7 and 28 days postoperatively. RESULTS: Treated-electrodes generate less sticking tissues and adhesive blood cells. Thermography revealed that the surgical temperature in liver tissue from the treated-electrode was significantly lower than the untreated-electrode. Total injury area of livers treated with treated-electrodes was significantly smaller than the untreated-electrodes treatment. Moreover, treated-electrodes caused a relatively smaller area of lateral thermal injury, a smaller area of fibrotic tissue and a faster process of remodeling than the untreated-electrodes. Western blot analysis showed that rats treated with treated-electrode expressed lower levels of NF-κB, caspase-3 and MMP-9 than untreated-electrode. Immunofluorescence staining for caspase-3 revealed that the untreated-electrode caused more serious injury. CONCLUSIONS: This study reveals that the plating of electrodes with hydrogenated Cu-incorporated diamond-like carbon film is an efficient method for improving the performance of electrosurgical units, and should benefit wound remodeling. However, more tests must be carried out to confirm these promising findings in human patients.

Osseointegration of titanium implants with SLAffinity treatment: a histological and biomechanical study in miniature pigs.

PURPOSE: Electrochemical oxidation following sandblasting and acid-etching (SLA) treatment has received interest as a surface modification procedure for titanium (Ti) implants (denoted as an SLAffinity surface); however, little information is available on its impacts on the in vivo performance of SLAffinity-Ti implants. The present study evaluated the osseointegration and biomechanical bone-tissue response to SLAffinity-Ti implants with micro- and nanoporous oxide layers. MATERIALS AND METHODS: The interaction between blood and the tested implants was examined. In total, 144 implants with the following surfaces were used: a standard machined (M-Ti), an SLA-Ti, and an SLAffinity-Ti surface. For each animal, four implants (one M-Ti, one SLA-Ti, and two SLAffinity-Ti) were inserted into the mandibular canine-premolar area for histomorphometric observations and another four implants were inserted into the flat surface on the anteromedial aspect of the rear tibia for removal torque (RT) tests. After 2, 4, and 8 weeks of implantation, histomorphometric and RT tests were conducted. RESULTS: Interactions between blood and implants were better for implants with the SLAffinity-Ti surface. RT tests showed a significant improvement in fixation strength for SLAffinity-Ti implants (84.5 ± 8.7 N-cm) after 8 weeks compared to M-Ti (62.95 ± 11.5 N-cm) and SLAffinity-Ti (76.1 ± 6.6 N-cm) implants. A histological evaluation showed that osseous integration had occurred with all implants after 8 weeks. SLAffinity-Ti implants exhibited 28.5 ± 6.2 % bone-to-implant contact (BIC) at 2 weeks and 84.3 ± 8.1 % at 8 weeks. M-Ti implants exhibited BIC levels of 17.0 ± 5.4 and 76.5 ± 6.3 %, whereas SLA-Ti implants exhibited BIC levels of 28.5 ± 6.2 and 81.1 ± 8.4 % at corresponding time intervals. In terms of the peri-implant bone area (BA), values for SLAffinity-Ti implants ranged from 29.5 ± 4.1 to 88.3 ± 3.0 %. For M-Ti implants, values ranged from 20.3 ± 5.5 to 81.7 ± 4.2 %. For SLA-Ti implants, values ranged from 23.0 ± 3.5 to 84.0 ± 3.6 %. CONCLUSIONS: Electrochemical oxidation increased the oxide layers and improved the blood interaction with SLAffinity-Ti implants, resulting in significantly higher bone apposition with the SLAffinity-Ti implants after 2 and 8 weeks of healing. An increase in resistance for the RT of SLAffinity-Ti implants over the 8-week healing period was also observed. CLINICAL RELEVANCE: The use of SLAffinity-Ti implants has potential for improvement of early osseointegration.

Sleep bruxism: an updated review of an old problem.

Objective To provide an update on what is known about bruxism and some of the major clinical highlights derived from new insights into this old problem in dentistry. Materials and methods A selective, non-systematic but critical review of the available scientific literature was performed. Results There are two main different types of bruxism, which are related to different circadian periods (sleep and awake bruxism) that may differ in terms of pathophysiology, but they share some common signs and symptoms. Approximately one out of 10 adult individuals may suffer from bruxism, but not all bruxers may need treatment. Bruxism is complicated to diagnose in the clinic and self-report of bruxism may not necessarily reflect the true presence of jaw muscle activity. Better understanding has been acquired of bruxism relationships with sleep stages, arousal responses and autonomic function with the help of polysomnography and controlled sleep studies. Meanwhile, there is still much more to learn about awake bruxism. With the available scientific knowledge it is possible to systematically assess the effects of bruxism and its potential risk factors for oral and general health. Moreover, we can be aware of the realistic possibilities to manage/treat the patient suffering from bruxism. Conclusion Bruxism is a parafunctional activity involving the masticatory muscles and probably it is as old as human mankind. Different ways have been proposed to define, diagnose, assess the impact and consequences, understand the pathophysiology and treat or manage bruxism. Despite the vast research efforts made in this field, there are still significant gaps in our knowledge.

Research of StemBios Cell Therapy on Dental Implants Containing Nanostructured Surfaces: Biomechanical Behaviors, Microstructural Characteristics, and Clinical Trial.

PURPOSE: The aim of the present study was to examine the osseointegration in low-density bone tissue for SLAffinity-treated implants with StemBios (SB) cell therapy. MATERIALS AND METHODS: The morphologies of SLAffinity-treated surfaces were characterized using scanning electron microscopy. In the animal model, implants were installed in the mandibular canine-premolar area of 12 miniature pigs. Each pig received 3 implants of machine, sand blasted, large grit, and acid etched, and SLAffinity-treated implants. In the clinical trial, 10 patients received 1 SLAffinity-treated implant in the maxilla in the posterior area and 1 patient with low bone tissue density received 2 SLAffinity-treated implants with SB cell therapy. Resonance frequency analysis and computed tomography were assessed monthly over the first 3 months after implant placement. RESULTS: The results demonstrated that surface treatment significantly affected early osseointegration in patients who received SB cell therapy. SB cell therapy transferred the stress caused by the implant more uniformly, and the stress decreased with healing time. SLAffinity-treated implants also proved clinically successful after the 3 months. CONCLUSION: The SLAffinity treatments enhanced osseointegration significantly, especially at early stages of bone tissue healing with SB cell therapy.

Rapid Osseointegration of Titanium Implant With Innovative Nanoporous Surface Modification: Animal Model and Clinical Trial.

OBJECTIVES: SLAffinity is the hybrid topography consisting of micropits and nanoporous TiO2 layers through electrochemical oxidation to mimic the natural bony environment. The aim of this study was to examine the rate of osseointegration in animal models and to further investigate the stability for implants with SLAffinity-treated surface in the clinical trial. MATERIALS AND METHODS: Implants were installed in the mandibular canine-premolar area of 12 miniature pigs. Each pig received 2 implants with the same shapes but with different chemical surfaces. In the clinical trial, 25 patients were included. Each patient received 1 SLAffinity-treated implant on the posterior area of either arch. Resonance frequency analysis and computed tomography were assessed weekly over the first 12 weeks after implant placement. RESULTS: The results found that surface treatment did affect the bone-to-implant contact (BIC) significantly. Comparison of BIC at 3 weeks in animal study showed that the SLAffinity-treated implants presented significantly higher values than machine surface implants. SLAffinity-treated implants also proved clinically successful through 12 months, ready for prosthodontic restoration. CONCLUSION: The effect of SLAffinity treatments enhanced osseointegration significantly, especially at early stages of bone healing. Clinical trial finding, furthermore, ensured that the SLAffinity treatment was a reliable surface modification alternative.

Biomedical nanostructured coating for minimally invasive surgery devices applications: characterization, cell cytotoxicity evaluation and an animal study in rat.

BACKGROUND: Thermal injury and tissue sticking, which influence wound remodeling, are major concerns in electrosurgery. In this study, the effect of lateral thermal injury caused by different electrosurgical electrodes on hepatic remodeling was investigated. METHODS: A monopolar electrosurgical unit equipped with untreated stainless steel (SS) and chromium nitride coated stainless steel (CrN-SS) electrodes was used to create lesions on the liver lobes of adult rats. Animals were sacrificed for evaluations at 0, 3, 7, and 28 days postoperatively. RESULTS: CrN-SS needles generated lower levels of sticking tissue, and the thermographs showed that recorded highest temperature in liver tissue from the CrN-SS needle group was significantly lower than in the SS needle group. The total injury area of livers treated with CrN-SS needles was significantly lower than livers treated with SS needles at each time point. Moreover, the CrN-SS needles caused a relatively smaller area of lateral thermal injury, a smaller area of fibrotic tissue, and a faster process of hepatic remodeling in rat liver than the SS needles. Immunofluorescence staining and Western blot analysis showed that rats treated with CrN-SS needles expressed lower levels of NF-κB and caspase-3 postoperatively. CONCLUSIONS: This study reveals that the plating of electrodes with a CrN film is an efficient method for improving the performance of electrosurgical units and should benefit wound remodeling. However, more tests must be performed to confirm these promising findings in human patients.

Effect of recombinant human bone morphogenetic protein-2 and Ling Zhi-8 on osteogenesis: a comparative study using a rabbit sinus model.

PURPOSE: This study evaluated the osteogenetic capability of Ling Zhi-8 (LZ-8; a protein purified from traditional Chinese medicine [lingzhi]) compared with recombinant human bone morphogenic protein-2 (rhBMP-2) in a standardized bony defect using a rabbit sinus model. MATERIALS AND METHODS: Twelve male New Zealand white rabbits (18 to 24 weeks old, 3.3 to 3.8 kg) were included in the study. Implants of normal saline 0.1 mg, rhBMP-2 0.1 mg, and LZ-8 0.1 mg were each mixed with a uniform biodegradable polyurethane-based material (Nasopore). The implants were inserted in a standardized bony defect of the nasal bone created by a 2.5-mm trephine bur. The rabbits were sacrificed at 1, 2, 4, and 8 weeks postoperatively. Volume computerized tomographic and histomorphometric examinations were used to evaluate the quantity and quality of regenerated bone. RESULTS: At postoperative week 4, radiography showed that the new bone volume was significantly larger in the rhBMP-2 group compared with the LZ-8 group (P = .041) and the control group (P = .015). Histomorphometrically, better wound healing of the rhBMP-2 group was found during the healing phase compared with the other 2 groups. CONCLUSION: The biomaterial implants using rhBMP-2 and LZ-8 had good biocompatibility and osteogenetic capabilities in the rabbit sinus model. Bone healing in rhBMP-2-treated defects was excellent and showed a significant difference compared with LZ-8. However, LZ-8-treated defects also exhibited bone regeneration, and this traditional Chinese medicine may possess osteogenic potential. Further investigations of the mechanism and application of this protein in osteogenesis are needed.

Cellular response of calcium phosphate bone substitute containing hydroxyapatite and tricalcium phosphate.

PURPOSE: This study developed calcium phosphate bone substitutes and their microstucture and in vitro cell response were evaluated in comparison with commercial hydroxyapatite (HA). MATERIALS: HA powder was ball-milled and then sintered to transfer into the calcium phosphate bulks (CPB). The density, hardness, and microstructure of the CPB were investigated. The viability and proliferation of MG63 osteoblast-like cells on the commercial HA and the CPB were evaluated. RESULTS: The x-ray diffraction confirmed that the CPB consisted of α-tricalcium phosphate (α-TCP), CaO, and HA. The hardness, density, and α-TCP-to-HA ratio of the CPB decreased when increasing the sintering duration. Cell tests demonstrated that the CPB exhibited an earlier cell-spread response than the commercial HA. CONCLUSIONS: This study demonstrated that a phase transformation of HA into α-TCP and CaO was achieved by sintering. The cell tests indicated that the CPB has favorable in vitro cellular performance, which implied that it presented potential as bone substitute.

Follow-up study of dental implants with bioactive oxide films on bone tissue healing and osseointegration: clinical radiography and bone quality analysis.

OBJECTIVE: The purpose of this study was to investigate osseointegration and bone stress resulted during the first 3 months after the installation of functional implants modified with bioactive oxide. METHODS: Several studies have investigated finite element models for dental implants; however, only a few have examined a model for the implants during different stages of osseointegration. In this study, mandible models were reconstructed using computer tomographic data, and bone qualities and stress distributions were investigated as well. RESULTS: Bone quality increased rapidly within the 3-month bone healing time. Data analysis indicated that the bone stresses increased with the progress of osseointegration, and the maximum stresses were obtained at the position around the first screw. CONCLUSION: The results confirmed that functional films could improve the biomechanical properties of the implants and promote the initial bone stability. Furthermore, potential clinical benefit can be obtained due to the inducing superior biomechanical behavior in dental implants.

Development of 3D in vitro technology for medical applications.

In the past few years, biomaterials technologies together with significant efforts on developing biology have revolutionized the process of engineered materials. Three dimensional (3D) in vitro technology aims to develop set of tools that are simple, inexpensive, portable and robust that could be commercialized and used in various fields of biomedical sciences such as drug discovery, diagnostic tools, and therapeutic approaches in regenerative medicine. The proliferation of cells in the 3D scaffold needs an oxygen and nutrition supply. 3D scaffold materials should provide such an environment for cells living in close proximity. 3D scaffolds that are able to regenerate or restore tissue and/or organs have begun to revolutionize medicine and biomedical science. Scaffolds have been used to support and promote the regeneration of tissues. Different processing techniques have been developed to design and fabricate three dimensional scaffolds for tissue engineering implants. Throughout the chapters we discuss in this review, we inform the reader about the potential applications of different 3D in vitro systems that can be applied for fabricating a wider range of novel biomaterials for use in tissue engineering.

Feasibility and Preliminary Efficacy of α-Calcium Sulfate Hemihydrate in Socket Preservation: Protocol for a Pilot Randomized Controlled Trial.

BACKGROUND: Tooth extraction procedures often lead to bone resorption, which can have adverse effects on the dimensions of the alveolar ridge. Research has shown that socket preservation techniques using bone graft substitutes can effectively minimize early bone loss in such cases. α-calcium sulfate hemihydrate (α-CSH) has garnered significant attention as a potential bone graft material due to its favorable properties, including osteoconductivity, angiogenic potential, and biocompatibility. Considering these facts, we developed a preliminary protocol for applying α-CSH in addressing alveolar bone loss following tooth extraction. OBJECTIVE: This research's general objective is to evaluate the feasibility and initial effectiveness of α-CSH as bone-inducing graft material for socket preservation after tooth extraction. METHODS: This preliminary clinical trial will involve 30 fresh extraction sockets from individuals aged 18-35 years. The participants will be divided into 2 groups: one group will receive α-CSH graft material after tooth extraction for socket preservation, while the other group will not receive any graft material. Throughout the study, the participants will be closely monitored for safety measures, which will include clinical examinations, radiographic imaging, and blood tests. Radiographic imaging will be used extensively to assist the progress of bone formation. RESULTS: The study commenced enrollment in August 2022 and is scheduled to conclude post assessments and analyses by the end of 2023. The results of the study are anticipated to be accessible in late 2024. CONCLUSIONS: This clinical study represents the initial investigation in humans to assess the feasibility and efficacy of α-CSH in alveolar bone regeneration. We hypothesize that the inclusion of α-CSH can greatly expedite the process of bone formation within fresh sockets, resulting in a swift restoration of bone height without the disadvantages associated with harvesting autogenous bone graft. TRIAL REGISTRATION: Indonesia Registry Center INA-D02FAHP; https://tinyurl.com/2jnf6n3s. INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID): DERR1-10.2196/49922.

Antibacterial nanostructured composite films for biomedical applications: microstructural characteristics, biocompatibility, and antibacterial mechanisms.

Hydrogenated Cu-incorporated diamond-like carbon (a-C:H/Cu) films were prepared in the present study using a radio-frequency plasma magnetron sputtering system at various CH4/Ar gas ratios. The a-C:H/Cu films were characterized by scanning electron microscopy, atomic force microscopy, Raman spectroscopy, transmission electron microscopy, nano-indentation and a contact angle goniometer. The antibacterial properties and cell cytotoxicity of a-C:H/Cu films were evaluated as per JIS Z2801:2010 and ISO 10993-5 specifications, respectively. The analytical results revealed that the production of a-C:H/Cu films varied with the CH4/Ar ratio, and the phase transformation (amorphous-like → nano-polycrystalline structure) was induced by Cu doping/ion bombardment and radical reactions. Moreover, it was found that the microhardness of the a-C:H/Cu films decreased with increasing Ar fraction in the gas ratio. The a-C:H/Cu films exhibited a high hydrophobic surface feature. The film which contained 77.3 ± 4.4 at.% Cu did not influence cell adhesion and proliferation behaviors. Antibacterial tests also demonstrated that a-C:H/Cu films possessed excellent antibacterial properties. Therefore, a-C:H/Cu films could be developed as promising antibacterial coatings for biomedical applications.

The effect of titanium with electrochemical anodization on the response of the adherent osteoblast-like cell.

PURPOSE: The osseointegration of titanium dental implants is essential for successful therapy, and this is strongly affected by the surface chemistry and roughness. In this study, using electrochemical anodization after sand blasting, and acid etching of Ti surface (SLA), SLA specimens with the high wettability of the thick TiO2 layer (SLAffinity) surface was developed to superimpose the nanoscale topographies on the microscale roughness of SLA surface without greatly altering the surface features. MATERIALS: The surface characteristics of SLAffinity specimens were investigated using scanning electron microscopy, atomic force microscopy, and x-ray photoelectron spectroscopy. The viability and proliferation of osteoblast-like cells (MG63 cells), which were seeded on SLAffinity specimens, were analyzed. RESULTS: Such electrochemically anodized specimens were predominantly composed of bioactive TiO2. The cell culturing tests revealed that the microscale roughness in combination with the nanoscale structures and bioactive properties improved osteoblast viability and differentiation on the SLAffinity surface. CONCLUSION: The favorable biological response of SLAffinity surfaces to MG63 osteoblast-like cells suggested that electrochemical anodization after SLA treatments is a potential procedure for better osseointegration in vivo.

2,3,5,4'-Tetrahydroxystilbene-2-O-ß-glucoside Attenuates Reactive Oxygen Species-Dependent Inflammation and Apoptosis in Porphyromonas gingivalis-Infected Brain Endothelial Cells.

We recently reported that the periodontopathic bacteria Porphyromonas gingivalis (P. gingivalis) initiates an inflammatory cascade that disrupts the balance of reactive oxygen species (ROS), resulting in apoptotic cell death in brain endothelial cells. An extract from Polygonum multiflorum Thunb., 2,3,5,4'-Tetrahydroxystilbene-2-O-ß-glucoside (THSG) has been well-reported to diminish the inflammation in many disease models. However, the effects of THSG in the area of the brain-oral axis is unknown. In this study, we examined the effects of THSG in P. gingivalis-stimulated inflammatory response and apoptotic cell death in brain endothelial cells. THSG treatment remarkably lessened the upregulation of IL-1ß and TNF-α proteins in bEnd.3 cells infected with P. gingivalis. Treatment of THSG further ameliorated brain endothelial cell death, including apoptosis caused by P. gingivalis. Moreover, the present study showed that the inhibitory effects on NF-κB p65 and antiapoptotic properties of THSG is through inhibiting the ROS pathway. Importantly, the ROS inhibitory potency of THSG is similar to a ROS scavenger N-Acetyl-L-Cysteine (NAC) and NADPH oxidase inhibitor apocynin. Furthermore, the protective effect of THSG from P. gingivalis infection was further confirmed in primary mouse brain endothelial cells. Taken together, this study indicates that THSG attenuates an ROS-dependent inflammatory response and cell apoptosis in P. gingivalis-infected brain endothelial cells. Our results also suggest that THSG could be a potential herbal medicine to prevent the risk of developing cerebrovascular diseases from infection of periodontal bacteria.

Three-Dimensional Printing of a Hybrid Bioceramic and Biopolymer Porous Scaffold for Promoting Bone Regeneration Potential.

In this study, we proposed a three-dimensional (3D) printed porous (termed as 3DPP) scaffold composed of bioceramic (beta-tricalcium phosphate (ß-TCP)) and thermoreversible biopolymer (pluronic F-127 (PF127)) that may provide bone tissue ingrowth and loading support for bone defect treatment. The investigated scaffolds were printed in three different ranges of pore sizes for comparison (3DPP-1: 150−200 µm, 3DPP-2: 250−300 µm, and 3DPP-3: 300−350 µm). The material properties and biocompatibility of the 3DPP scaffolds were characterized using scanning electron microscopy, X-ray diffractometry, contact angle goniometry, compression testing, and cell viability assay. In addition, micro-computed tomography was applied to investigate bone regeneration behavior of the 3DPP scaffolds in the mini-pig model. Analytical results showed that the 3DPP scaffolds exhibited well-defined porosity, excellent microstructural interconnectivity, and acceptable wettability (θ < 90°). Among all groups, the 3DPP-1 possessed a significantly highest compressive force 273 ± 20.8 Kgf (* p < 0.05). In vitro experiment results also revealed good cell viability and cell attachment behavior in all 3DPP scaffolds. Furthermore, the 3DPP-3 scaffold showed a significantly higher percentage of bone formation volume than the 3DPP-1 scaffold at week 8 (* p < 0.05) and week 12 (* p < 0.05). Hence, the 3DPP scaffold composed of ß-TCP and F-127 is a promising candidate to promote bone tissue ingrowth into the porous scaffold with decent biocompatibility. This scaffold particularly fabricated with a pore size of around 350 µm (i.e., 3DPP-3 scaffold) can provide proper loading support and promote bone regeneration in bone defects when applied in dental and orthopedic fields.

Development of silver-containing austenite antibacterial stainless steels for biomedical applications part I: microstructure characteristics, mechanical properties and antibacterial mechanisms.

The as-quenched (AQ) microstructure of the Ag-containing alloys was found to be essentially a mixture of austenite (γ) and Ag phases. The Ag phase precipitates had a face-centered-cubic structure and lattice parameter a = 4.09 Å. When the alloy contained Ag ≥0.2 wt%, the mechanical properties were slightly enhanced because of the precipitate strengthening by the Ag phase precipitates. Moreover, the Ag-containing alloys exhibited ductile fracture after tensile testing. The results of an antibacterial test revealed that the Ag phase precipitates play a key role in the antibacterial mechanism of Ag-containing alloys: Ag(+) ions released from the Ag phase precipitates can kill bacteria. It is suggested that as AISI 316L alloy has an Ag content ≥0.2 wt%, it will have excellent antibacterial properties against both Staphylococcus aureus and Escherichia coli, with an antibacterial rate of nearly 100%.

Porphyromonas gingivalis Induces Proinflammatory Cytokine Expression Leading to Apoptotic Death through the Oxidative Stress/NF-κB Pathway in Brain Endothelial Cells.

Porphyromonas gingivalis, a periodontal pathogen, has been proposed to cause blood vessel injury leading to cerebrovascular diseases such as stroke. Brain endothelial cells compose the blood-brain barrier that protects homeostasis of the central nervous system. However, whether P. gingivalis causes the death of endothelial cells and the underlying mechanisms remain unclear. This study aimed to investigate the impact and regulatory mechanisms of P. gingivalis infection in brain endothelial cells. We used bEnd.3 cells and primary mouse endothelial cells to assess the effects of P. gingivalis on endothelial cells. Our results showed that infection with live P. gingivalis, unlike heat-killed P. gingivalis, triggers brain endothelial cell death by inducing cell apoptosis. Moreover, P. gingivalis infection increased intracellular reactive oxygen species (ROS) production, activated NF-κB, and up-regulated the expression of IL-1ß and TNF-α. Furthermore, N-acetyl-L-cysteine (NAC), a most frequently used antioxidant, treatment significantly reduced P. gingivalis-induced cell apoptosis and brain endothelial cell death. The enhancement of ROS production, NF-κB p65 activation, and proinflammatory cytokine expression was also attenuated by NAC treatment. The impact of P. gingivalis on brain endothelial cells was also confirmed using adult primary mouse brain endothelial cells (MBECs). In summary, our results showed that P. gingivalis up-regulates IL-1ß and TNF-α protein expression, which consequently causes cell death of brain endothelial cells through the ROS/NF-κB pathway. Our results, together with the results of previous case-control studies and epidemiologic reports, strongly support the hypothesis that periodontal infection increases the risk of developing cerebrovascular disease.